Nothing astonishing about it at all. Particularly if you consider the duration – for how long the thing is able to produce that lift. As anyone who has actually handled an assault rifle (instead of just seeing it in the movies) knows, yes, there is some recoil, but if you set the selector to full auto and keep shooting, you’ll have emptied your magazine in about three seconds.

Gareth – A hawk is far too light to support any decent RAILgun (redundant array of independant lasers) and the training you’d need to put in would obviate the use of a creature that naturally predates upon squirrels – no need to harness natural killing instincts when we will be implanting those skills along with the technical/combat training.

I suggest we use giraffes, although because herbivores tend to have sub-standard eyesight we’ll need some kind of auxiliary ocular augmentation.

In summary, head-mounted laser cannon with a HUD and a saddle-mounted battery pack.

@diog, it is an expression of wonderment at the number of things that “every schoolboy knows” that Tim doesn’t. I blame that Downside.

(Though I admit that my pal who went to Ampleforth refers to it as ‘St Ignoramus’. That was in the period when good state schools were distinctly better than all but the very best public schools. Long gone days.)

I think we are missing the important question. Somewhere, in a Jerry Pournelle book I think which means it must have been King David’s Rocket, he has a primitive society launch a rocket into space using a bunch of downward firing quick fire guns.

So – could Britain’s next satellite launch use a lot of Army surplus SA-80s strapped to the bottom of a Robin Reliant? I think that is the real issue here.

Top Gear launched a Reliant Robin into space once. When I say “launched into space”, I mean “launched in the direction of space”; it did not get very far.

On the amazingness or not of the quoted fact, it’s a bit like the oft quoted fact that spider silk is stronger than steel – amazing until you think of the sheer difference in scale between a web strand and a steel girder, or even a steel pin, then not so amazing. What makes a pin different from a web strand is only peripherally the load bearing capacity per cross sectional area, and what makes an AK-47 different from a Saturn 5 is only peripherally the thrust to weight ratio.

In a much better book than any of those referenced above (Iain Banks’s Walking On Glass), a soldier in an advanced alien race is punished for firing his automatic rifle to break his fall when he falls off a high roof – the punishment since he’s on crowd control sniper duty at a coronation at the time and takes out a dozen bystanders.

I’m pleased to discover, 20 years on, that this is factually plausible-ish.